VB.Net Tutorial/Socket Network/TcpClient

Create TcpClient

Imports System.Net.Sockets
Imports System.Net
Imports System.Threading
Imports System.Text
Public Class Tester
    
    Public Shared Sub Main
        Dim myTcpClient As New TcpClient()
        Try
            myTcpClient.Connect("127.0.0.1", 1234)
        Catch ex As ArgumentOutOfRangeException
            Console.WriteLine(ex.Message)
        Catch ex As SocketException
            Console.WriteLine(ex.Message)
        End Try
    End Sub
End Class

No connection could be made because the target machine actively refused it

Date time client based on TcpClient

Imports System
Imports System.IO
Imports System.Net
Imports System.Net.Sockets
Imports System.Text
Public Class DateTimeClient
  Public Shared Sub Main()
    Dim args As String() = Environment.GetCommandLineArgs()
    Dim serverHost As String = "127.0.0.1"
    Try
      Dns.GetHostByName(serverHost)
    Catch ex As Exception
      Console.WriteLine("Can not find server, {0}", serverHost)
      Exit Sub
    End Try
    Dim tcpClient As New TcpClient()
    Dim networkStream As Stream
    Try
      tcpClient.Connect(serverHost, 13)
      networkStream = tcpClient.GetStream()
    Catch exc As Exception
      Console.WriteLine("Can not connect to {0}", serverHost)
      Exit Sub
    End Try
    Try
      If networkStream.CanRead Then
        Dim recvbytes(tcpClient.ReceiveBufferSize) As Byte
        Dim i As Integer = networkStream.Read(recvbytes, 0, CInt(tcpClient.ReceiveBufferSize))
        Dim datetime As String = Encoding.ASCII.GetString(recvbytes, 0, i)
        Console.WriteLine("Receive {0} bytes.", i)
        Console.WriteLine("Current server date/Time: {0}", datetime)
      Else
        Console.WriteLine("Network Input Stream is unreadable.")
        tcpClient.Close()
        Return
      End If
    Catch ec As Exception
      Console.WriteLine(ec.StackTrace.ToString())
      Exit Sub
    End Try
    tcpClient.Close()
  End Sub
End Class

Can not connect to 127.0.0.1